Pharmaceutical Care of Epilepsy Flashcards
What is epilepsy?
Sudden burst of intense electrical activity in the brain
What is the most common type of seizures?
Focal seizure
What is a focal seizure?
Burst of electrical activity happens in a specific part of the brain (focal point)
What is the common site of a focal seizure?
Temporal lobe
What can a focal seizure do?
Can spread from focal point to entire brain
What are the different parts of the brain?
Parietal lobe (back at top)
Frontal lobe (front)
Temporal lobe (middle)
Occipital lobe (at the back (small))
What is the other type of seizures?
Generalised seizures
What are the different type of generalised seizures?
Atonic seizures
Tonic-clonic seizure
Myoclonic seizures
Tonic seizures
Absence seizures
Describe an atonic seizure
Sudden loss of muscle control
Slump/fall forward
Head may drop
Describe a tonic-clonic seizure
Normally get aura but can happen without
Body stiffens = phase 1
Body shakes = phase 2
Describe a myoclonic seizure
Muscle spasms = localised to certain body parts
What age does myoclonic seizures most occur in?
Ages 3 - 12 = younger patients
Describe a tonic seizure
Body stiffens
Arms + legs
Fall backwards
Incontinence
Back arched
Describe an absence seizure
Blank stare
NO rapid movements/involuntary movements
Blink rapidly/roll their eyes
What is a generalised seizure?
Affects entire brain
What other conditions may present similar epilepsy?
Vasovagal syncope (fainting)
Pseudoseizures (non-epileptic attacks)
Cardiac syncope
Hypoglycaemia
Hemiplegic migraine
Transient ischaemic attack
What investigations can be done?
Clinical presentation
Medical history
Family history
EEG
ECG
MRI
Blood tests = FBC, U&Es + CBG
What is the impact on daily life?
Loss of license
Baths/swimming = risk of drowning
Employment/education
How do you manage epilepsy?
Dependent on seizure type
Tailored + specialised
Titration based on tolerance + efficacy
What is the treatment goal?
Seizure-free on minimum number of antiepileptics
What is crucial with AEDs?
ADHERENCE = OD + BD dosing
What is the treatment for focal seizures?
1st line = Lamotrigine or Levetiracetam
IF unsuccessful = Carbamazepine, Oxcarbazepine + Zonisamide
What is the treatment for tonic-clonic seizures?
1st line = sodium valproate
Alternative = Lamotrigine or Levetiracetam
What is the treatment for tonic/atonic seizures?
1st line = sodium valproate
Alternative = Lamotrigine
What is the treatment for absence seizures?
1st line = Ethosuximide
2nd line/ add-on = sodium valproate
What is the treatment for myoclonic seizures?
1st line = sodium valproate
Alternative = Levetiracetam
What is the main drug for generalised seizures?
WRITE IN AN EXAM
Sodium valproate
What are the different ways the medicines work?
Na+ inhibitor
Enhance GABA
Ca2+ inhibitors = absence seizures
What is the problem with sodium valproate?
Highly teratogenic
= NEED to be enrolled into pregnancy prevention programme
What needs to be done when supplying sodium valproate?
Script valid for 7 days
Need sufficient contraception
Only give 30 day supply
Supply alert card
What are the side effects of sodium valproate?
Hepatoxicity
Blood dyscrasias - thrombocytopenia
Pancreatitis
Weight gain
CNS = aggression, confusion + drowsiness
Transient hair loss
What are the counselling points for hepatoxicity?
Jaundice (eyes + skin yellow)
Vomiting drowsiness
What is the monitoring for hepatoxicity?
Monitor LFTS + clotting factors if signs/symptoms suggest
What are the counselling points for blood dyscrasias - thrombocytopenia (low platelets)?
Easy bleeding
Sore throat
Fever
What are the investigation for blood dyscrasias?
FBC
What are the counselling points for pancreatitis?
Abdomen pain
N+V
What is the investigation for pancreatitis?
Amylase test
What needs to be considered with other medications when using sodium valproate?
Medications that lower seizure threshold
Medications that may cause hepatoxicity
Medicines that antagonise AED effect = increase risk of seizure
What are medicines that antagonise AED effect?
Quinolones
SSRIs
TCAs
Antipsychotics
What are the CYP450 inhibitors?
SICKFACES.COM
Sodium valproate
Isoniazid
Cimetidine
Ketoconazole
Fluconazole
Alcohol + grapefruit juice
Chloramphenicol
Erythromycin
Sulfonamides
Ciprofloxacin
Omeprazole
Metronidazole
What is good about Lamotrigine?
Long t1/2 = take less frequently
What are the side effects of Lamotrigine?
Rash - Steven Johnson Syndrome
N+V
Dizziness
Slight daytime drowsiness
What is the only other drug that gives the Steven Johnson Syndrome?
Allopurinol
What needs to be considered with other medications when taking Lamotrigine?
Contraceptives = decrease exposure
CYP450 inducers
CYP450 inhibitors
What are the CYP450 inducers?
CRAP GPs
Carbamazepine
Rifampicin
Alcohol
Phenytoin
Griseofulvin
Phenobarbitone
Sulphonylureas
What is good about Levetiracetam?
Used regularly PO + IV
Fewer drug interactions
What are the side effects of Levetiracetam?
Psychological (irritability, drowsiness + anxiety)
What is dangerous about Carbamazepine?
Narrow therapeutic index drug
Toxicity risk >12mg/L
What are the signs + symptoms of toxicity of carbamazepine?
Cerebellar signs = ataxia, nystagmus, drowsiness
Cardiovascular signs = arrhythmias, tachycardia, hyper/hypotension
Electrolyte disturbances = decreased Na+, decreased K+, increased CBGs
What are the side effects of Carbamazepine?
Blood dyscrasias
Hepatoxicity
Rash
Hyponatremia
What are the considerations for other medications when taking Carbamazepine?
Medications that lower seizure threshold
Medications may cause hepatoxicity
Medications that antagonise AED effects
Enzyme inhibitors
Enzyme inducers
Medicines that lower Na+
Which medicines are advised that you stay on the same brand?
Carbamazepine
Phenytoin
Phenobarbital
Primidone
Which medicines are advised you can change brand BUT only based clinical judgment?
Sodium valproate
Lamotrigine
Which medicine does it NOT matter if you change brand?
Levetiracetam
How do you avoid AED withdrawal?
Gradual dose reduction
Avoid abrupt withdrawal
One medicine at a time
What is status epilepticus?
Medical emergency
= seizure that lasts longer than 5 mins OR more than 1 seizure within 5 mins
What is the treatment for status epilepticus?
IV Lorazepam = preferred = lower risk of thrombophlebitis
IV diazepam = effective
What is thrombophlebitis?
Inflammation of blood vessels
What is the problem with Phenytoin?
NOT used much anymore
High risk = narrow therapeutic window
Phenytoin sodium NOT bioequivalent to phenytoin base
IV = needs large vein through large gage needle
What are the signs of phenytoin toxicity?
>20mg/L
Slurred speech
Nystagmus (eye movement) = 30mg/L
Ataxia
Confusion
Hyperglycaemia
Blurred vision
What are the side effects of Phenytoin?
Blood dyscrasias
Rashes
Low vit D
Hepatoxicity
What are the interactions for Phenytoin?
Medicines that antagonise AED effect#
Enzyme inhibitors
Enzyme inducers
Other antifolate medicines
